INFO: task syz-executor0:11391 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #171 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D22464 11391 4409 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:715 [inline] chown_common+0x3a9/0x730 fs/open.c:640 do_fchownat+0x16e/0x250 fs/open.c:673 __do_sys_lchown fs/open.c:698 [inline] __se_sys_lchown fs/open.c:696 [inline] __x64_sys_lchown+0x7e/0xc0 fs/open.c:696 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456a09 Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b RSP: 002b:00007feeccfd9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000005e RAX: ffffffffffffffda RBX: 00007feeccfda6d4 RCX: 0000000000456a09 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d13d8 R14: 00000000004c6d1b R15: 0000000000000000 INFO: task syz-executor0:11455 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #171 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23208 11455 4409 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 request_wait_answer+0x4c8/0x920 fs/fuse/dev.c:463 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:483 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:496 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:554 fuse_lookup_name+0x3ee/0x830 fs/fuse/dir.c:323 fuse_lookup+0xf9/0x4c0 fs/fuse/dir.c:360 __lookup_slow+0x2b5/0x540 fs/namei.c:1630 lookup_slow+0x57/0x80 fs/namei.c:1647 walk_component+0x94a/0x2630 fs/namei.c:1769 lookup_last fs/namei.c:2237 [inline] path_lookupat.isra.45+0x202/0xbf0 fs/namei.c:2287 filename_lookup+0x264/0x510 fs/namei.c:2321 user_path_at_empty+0x40/0x50 fs/namei.c:2584 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x129/0x210 fs/stat.c:185 vfs_lstat include/linux/fs.h:3107 [inline] __do_sys_newlstat+0x8f/0x110 fs/stat.c:350 __se_sys_newlstat fs/stat.c:344 [inline] __x64_sys_newlstat+0x54/0x80 fs/stat.c:344 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456a09 Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b RSP: 002b:00007feeccef2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 00007feeccef36d4 RCX: 0000000000456a09 RDX: 0000000000000000 RSI: 00000000200009c0 RDI: 00000000200003c0 RBP: 0000000000930500 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d14f8 R14: 00000000004c6d78 R15: 0000000000000007 Showing all locks held in the system: 1 lock held by khungtaskd/773: #0: 00000000eb4ba8d1 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4272: 2 locks held by getty/4362: #0: 000000008ca7b4d7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000007a31b6fb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4363: #0: 00000000909b8bb9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003bb4adaf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4364: #0: 00000000527f1a69 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000386e79b7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4365: #0: 000000006c19c3ee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e62970b2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4366: #0: 00000000317cca3d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000011977c8a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4367: #0: 000000005b1d6afa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000eddf2f7f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4368: #0: 000000003565a774 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002bc72265 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor0/11391: #0: 0000000054351226 (sb_writers#15){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 0000000054351226 (sb_writers#15){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 0000000076839d51 (&type->i_mutex_dir_key#5){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 0000000076839d51 (&type->i_mutex_dir_key#5){++++}, at: chown_common+0x3a9/0x730 fs/open.c:640 2 locks held by syz-executor0/11455: #0: 0000000076839d51 (&type->i_mutex_dir_key#5){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 0000000076839d51 (&type->i_mutex_dir_key#5){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 #1: 000000000cde7a16 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc7+ #171 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54